A nonvolatile semiconductor memory device includes elements such as transistors, diodes, capacitors, and resistors. The elements are prepared in a form based on the film structure of a memory transistor in terms of memory manufacturing process.
The film structure of the memory transistor is formed by sequentially stacking a tunnel oxide film (gate insulating film), a floating gate layer, an inter-gate insulating film, and a control gate layer on a lowermost silicon substrate.
For the resistive element, since the floating gate layer has a relatively high resistance, the length of the floating gate layer is changed, and an interconnection is connected across it, thereby obtaining a desired resistance value. At this time, the control gate layer above the floating gate layer is partially cut in the subsequent process so as to be isolated and not to function as a resistor.
In the above-described resistance obtaining method, however, only the floating gate layer is used as the resistor. For this reason, only one kind of resistance value is obtained in a predetermined layout area, and it is difficult to obtain a plurality of resistance values.